增效磷对农药混剂的增效作用及增效比值研究

测定增效磷与氰戊菊酯、敌敌畏混用对褐稻虱和菜蚜的增效作用以及对其他几种害虫的增效比值结果表明，混剂对褐稻虱处理２４ｈ的触杀毒力ＬＣ５０值为１３．８５ｍｇ／ｋｇ，比单剂氰戊菊酯、敌敌畏和增效磷的触杀毒力分别高６．３５倍、２．５６倍和１．８６倍，共毒系数为２３９．７５，大于２００有明显增效作用。混剂对菜蚜处理２４ｈ的触杀毒力ＬＣ５０值为１．１０ｍｇ／ｋｇ，比单剂氰戊菊酯、敌敌畏和增效磷的触杀毒力分别高０．５倍、４．２倍和３２．５倍，共毒系数为２７１．３５，亦有明显增效作用。加有增效磷的混剂对棉蚜处理２４ｈ的触杀毒力ＬＣ５０值为３０．９９ｍｇ／ｋｇ，比不加增效磷混剂的增效比值高１．７倍；对棉红叶螨处理２４ｈ的触杀毒力ＬＣ５０值为４６．５７ｍｇ／ｋｇ，增效比值为１．７倍；对玉米螟处理２４ｈ的触杀毒力ＬＣ５０值为１１６．５０ｍｇ／ｋｇ，增效比值为２．０倍；对粘虫处理２４ｈ的触杀毒力ＬＣ５０值为２４．８１ｍｇ／ｋｇ，增效比值为１．３倍。

STUDIES ON ADDITIVE ACTION AND SYNERGIST RATIO OF SV 1 WITH MIXTURES OF INSECTICIDES TO SEVERAL PEST

The contact toxicities of SV 1 with mixtures of fenvalerate and DDVP to rice brown planthopper ( Nilaparvata lugens Stal) and cabbage aphids ( Lipahis erysimi Kallenbach) by meams of immerse and spray topical application methods were tested in laboratory. The results of experiment indicated that 24 h tested the LC 50 values of SV 1 with mixtures fenvalerate and DDVP was 13 85 mg/kg and the LC 50 values of single fenvalerate and DDVP and SV 1 were 87 88, 35.39 and 25 71 mg/kg to rice brown planthopper, respectively. The LC 50 values of contact toxicities were 6 34, 2 56 and 1 86 times as high as that of single insecticide to rice brown planthopper, respectively. After 24 h tested the results showed that the LC 50 values of SV 1 with of fenvalerate and DDVP was 1 10 mg/kg to cabbage aphid. The LC 50 valures were 0 5, 4 2 and 32 5 times as high as that of single inseticide to cabbage aphid, respectively. The co toxicity caefficient of SV 1 with of mixtures fenvalerate and DDVP were 239 75 and 271 35 to rice brown planthopper and cabbage aphids. The results of contact toxicities indicated that the LC 50 values SV 1 with fenvalerate and DDVP were 30 99, 46 57, 116 50 and 24 87 mg/kg to cotton aphids, two spotted spider mite, cornborer and army worm, respectively. After 24 h tested, the LC 50 values of SV 1 with mixtures fenvalerate and DDVP were 1 7, 1 7, 2 0 and 1 3 times higher than that of the mixture of fenvalerate and DDVP to several pests, respectively.